| Title: | "Foliar enrichment of copper oxide nanoparticles promotes biomass, photosynthetic pigments, and commercially valuable secondary metabolites and essential oils in dragonhead (Dracocephalum moldavica L.) under semi-arid conditions" |
| Author(s): | Nekoukhou M; Fallah S; Pokhrel LR; Abbasi-Surki A; Rostamnejadi A; |
| Address: | "Department of Agronomy, Faculty of Agriculture, Shahrekord University, Shahrekord, Iran. Department of Agronomy, Faculty of Agriculture, Shahrekord University, Shahrekord, Iran. Electronic address: fallah-s@sku.ac.ir. Department of Public Health, The Brody School of Medicine, East Carolina University, Greenville, NC, USA. Electronic address: pokhrell18@ecu.edu. Department of Electroceramics and Electrical Engineering, Malek Ashtar University of Technology, Iran" |
| DOI: | 10.1016/j.scitotenv.2022.160920 |
| ISSN/ISBN: | 1879-1026 (Electronic) 0048-9697 (Linking) |
| Abstract: | "High alkaline and low organic carbon hinder micronutrients, such as copper (Cu), bioavailability in (semi-) arid soils, affecting plant nutrient quality and productivity. This study aimed at investigating the potential beneficial effects of foliar Cu oxide nanoparticles (CuONPs) and conventional chelated-Cu applications (0-400 mg Cu/L) on the biomass, physiological biomarkers of plant productivity and oxidative stress, Cu bioaugmentation, and essential oils and secondary metabolites in dragonhead (Dracocephalum moldavica [L.]) grown in Cu-limited alkaline soil in semi-arid condition. Employing a randomized complete block design with three replicates, two different sources of Cu (CuONPs and chelated-Cu), and a wide range of Cu concentrations (0, 40, 80, 160, and 400 mg Cu/L), plants were foliarly treated at day-60 and day-74. At day-120, plants were harvested at the end of the flowering stage. Results showed shoot Cu bioaccumulation, flavonoids and anthocyanin increased in a dose-dependent manner for both Cu compounds, but the beneficial effects were significantly higher with CuONPs compared to chelated-Cu treatments. Further, shoot biomass (23 %), photosynthetic pigments (chlorophyll-a and chlorophyll-b; 77 and 123 %, respectively), and essential oil content and yield (70 and 104 %, respectively) increased significantly with foliar application of 80 mg/L CuONPs compared to equivalent concentration of chelated-Cu, suggesting an optimal threshold beyond which toxicity was observed. Likewise, commercially important secondary metabolites' yield (such as geranyl acetate, geranial, neral, and geraniol) was higher with 80 mg/L CuONPs compared to 160 mg/L chelated-Cu (2.3, 0.5, 2.5, and 7.1 %, respectively). TEM analyses of leaf ultrastructure revealed altered cellular organelles for both compounds at 400 mg/L, corroborating the results of oxidative stress response (malondialdehyde and H(2)O(2)). In conclusion, these findings indicate significantly higher efficacy of CuONPs, with an optimal threshold of 80 mg/L, in promoting essential oil and bioactive compound yield in dragonhead and may pave a path for the use of nano-Cu as a sustainable fertilizer promoting agricultural production in semi-arid soils that are micronutrient Cu deficient" |
| Keywords: | "Copper/toxicity/analysis *Oils, Volatile Biomass Hydrogen Peroxide/analysis *Nanoparticles Chlorophyll/metabolism Oxides Soil Copper oxide nanoparticles Dragonhead Essential oil Photosynthesis;" |
| Notes: | "MedlineNekoukhou, Marjan Fallah, Sina Pokhrel, Lok Raj Abbasi-Surki, Ali Rostamnejadi, Ali eng Randomized Controlled Trial Netherlands 2022/12/19 Sci Total Environ. 2023 Mar 10; 863:160920. doi: 10.1016/j.scitotenv.2022.160920. Epub 2022 Dec 16" |
